Here we are comparing two cameras with different body types: Pentax WG-3 is a Waterproof camera with a 16.0MP 1/2.3" sensor whereas Sony A7 is a Pro Mirrorless camera with a 24.0MP Full frame sensor. Comparing an interchangeble lens camera to a fixed lens camera is a bit tricky but we will do our best to make this a fair comparison.

Let's have a brief look at the main features of Pentax WG-3 and Sony A7 before getting into our more detailed comparison.

Below you can see the front view size comparison of Pentax WG-3 and Sony A7. Pentax WG-3 is clearly the smaller of the two cameras. Its body is 3mm narrower, 30mm shorter and 15mm thinner than Sony A7. As you can tell, actually this is not a fair size comparison since Pentax WG-3 has a built-in lens but Sony A7 doesn't. Once you put a lens on A7, its thickness will increase significantly.

Weight is another important factor especially when deciding on a camera that you want to carry with you all day.
Pentax WG-3 is significantly lighter (244g ) than the Sony A7 which may become a big advantage especially on long walking trips.

Again, this comparison may not be very useful in real life as we are comparing the weight of a camera with a built-in lens to the body-only weight of an interchangeable lens camera. Once you put a lens on A7, the total kit will weigh much higher.

Pentax WG-3 vs Sony A7: Sensor Comparison

Pentax WG-3 has a 16.0MP 1/2.3" (6.17 x 4.55 mm ) sized BSI-CMOS sensor . On the other hand, Sony A7 has a 24.0MP Full frame (35.8 x 23.9 mm ) sized CMOS sensor and features Bionz X processor. Sony A7's sensor provides 8MP more than Pentax WG-3's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.

Below you can see the WG-3 and A7 sensor size comparison.

As seen above, Sony A7 has a 30.5x Larger sensor area than Pentax WG-3. Larger sensors give photographer more control on the depth of field and blurry background compared to smaller sensor when shot in same focal length and aperture.

What types of Photography are Pentax WG-3 and Sony A7 Good for?

In this section, we rank and compare Pentax WG-3 and Sony A7 for five different photography types in order to make your decision process easier in case you are specifically interested in one or more of these areas.

You may have already made your decision about which camera suits better for your needs and your budget so far but in case you wonder how we rated Pentax WG-3 and Sony A7, below you can find their scores in five different aspects.
Our Decision Algorithm dynamically scores cameras using 63 different specs, current price and DxO Mark scores (where possible) in order to make a more objective and consistent comparison.

Here is a summary of how Pentax WG-3 and Sony A7 scores compare:

Pentax WG-3

Imaging

Features

Value

Portability

Overall

Ranked #48 out of 468 in Compact camerasRanked #386 out of 1131 in all Cameras

Sony A7

Imaging

Features

Value

Portability

Overall

Ranked #13 out of 49 in SLR-style mirrorless camerasRanked #39 out of 1131 in all Cameras

Sony A7 is the overall winner of this comparison. It has a higher Overall Score and beats Pentax WG-3 in all criterias except one: Portability.If small size and light body is a big priority for you, choose Pentax WG-3. Otherwise, Sony A7 is the better camera overall.